title: Time trend of medical economic outcomes of endoscopic submucosal dissection for gastric cancer in Japan: a national database analysis.
abstract: BACKGROUND
  Little information is available on the analysis of chronological changes in medical economic outcomes of endoscopic submucosal dissection (ESD) for gastric cancer. This study aimed to investigate the recent time trend of medical economic outcomes of ESD for gastric cancer based on the Japanese administrative database.
  
  
  METHODS
  A total of 32,943 patients treated with ESD for gastric cancer were referred to 907 hospitals from 2009 to 2011 in Japan. We collected patients' data from the administrative database to compare ESD-related complications, risk-adjusted length of stay (LOS), and medical costs during hospitalization. The study periods were categorized into three groups: 2009 (n = 9,727), 2010 (n = 11,052), and 2011 (n = 12,164).
  
  
  RESULTS
  No significant difference was observed in ESD-related complications between three study periods (p = 0.496). However, mean LOS and medical costs during hospitalization of patients with ESD were significantly lower in 2011 than in 2009 and 2010 (p < 0.001). Multiple linear regression analysis showed that patients who received ESD in 2011 had a significantly shorter LOS and lower medical costs during hospitalization compared with those in 2009. The unstandardized coefficient of patients with ESD in 2011 for LOS was -0.78 days [95 % confidence interval (CI), -0.89 to -0.65; p ≤ 0.001], while that of those for medical costs during hospitalization was -290.5 US dollars (95 % CI, -392.3 to -188.8; p ≤ 0.001).
  
  
  CONCLUSIONS
  This study showed that the complication rate of ESD was stable, whereas the LOS and medical costs of patients were significantly reduced from 2009 to 2011.
authors.affiliation: Department of Preventive Medicine and Community Health, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan, amurata@med.uoeh-u.ac.jp.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Murata
authors.forename: Kohji
authors.initials: K
authors.lastname: Okamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Muramatsu
authors.forename: Shinya
authors.initials: S
authors.lastname: Matsuda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004470:Economics, Medical; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000009:adverse effects*; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D006801:Humans; D006975:Hypertension, Portal / Q000150:complications / Q000191:economics* / Q000601:surgery; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000191:economics* / Q000209:etiology; D011379:Prognosis; D013274:Stomach Neoplasms / Q000150:complications / Q000191:economics* / Q000601:surgery; D015996:Survival Rate; D013997:Time Factors